The invention relates to the field of perfumery and in particular to the use of a substituted tetrahydro-pyran as a perfuming ingredient.
It is known from Swiss patent no. 655 932 that the hydro-pyrans of formula ##STR1## having an additional double bond in one of the positions indicated by the dotted lines and wherein R represents hydrogen or a lower alkyl radical, are useful starting materials for the synthesis of odorant molecules. There is no mention, however, nor even suggestion, in this document that the said compounds (I) might have any other potential usefulness, namely for the perfume industry.
On the other hand, the compound of formula ##STR2## is a known fragrance ingredient, commercialized under the tradenames of PELARGENE.RTM. (origin: PPF Int., UK) and FENYRANE.RTM. (origin: Naarden Int., Holland). The odor of compound (II) has been described as being of the rose-geranium, rose oxide type. We have found that PELARGENE.RTM. possesses a bitter, earthy, metallic note with some geranium character.
In a recent publication appearing in J. Org. Chem. 56, 5245 (1991), dealing with the cyclization of alkoxymethyl radicals, V. H. Rawal et al. have reported the preparation of a cyclization product which contained tetrahydro-4-methyl-2-phenyl-2H-pyran as a minor component. The latter does not appear to have been separated from the mixture obtained in the cyclization reaction and the article is totally mute as to the properties of the obtained products.
It is therefore quite unexpectedly that we have now discovered that tetrahydro-4-methyl-2-phenyl-2H-pyran possesses very useful odor properties.